How old is this?

Thanks for the replies. Customer is contacting the DNO for a visit. Ive never come across anything as old as this. I'd assumed it was a TN-s system but I cant see where they have taken the earth from to the property. There is certainly no spike around the outside of the building

Craig, thank you. Do please keep us updated. :-)

I cant see where they have taken the earth from to the property. There is certainly no spike around the outside of the building

The old tradition was to use the water supply pipe... in the day it would have already been there and made an excellent electrode - reliably metallic (if probably lead rather than copper) with excellent contact with the earth over a considerable distance and (mostly) buried sufficiently deep to avoid freezing.. Often the connection was a relatively thin bare stranded conductor (maybe as small as 1mm² equivalent) and sometimes connected to somewhere obscure like the back of a convenient socket near the stopcock rather than directly to the MET. The introduction of plastic supply pipes messed that up of course...

   - Andy.

The way to test the water pipe earth from the same era was not a Zs meter, but simply to connect a test lamp between live and earth - if it came on, there was a respectable earth connection, and as all lead pipe joints were soldered back then, it would actually have been pretty solid and maintenance free, forming a horizontal electrode of hundreds of metres in length, at least as far as any compression type repair or joint to a cast iron main where there may or may not have been something insulating on the threads in the joint..   

As I pointed out above, if it was early, the house earth connection probably came a few years after the electrical supply itself, when the sockets started to change from 2 pin to 3 pin and there was a need for something to connect it to. Note that the incomer may be lead sheathed, but that may or may not actually connect solidly to the service head, as there was often a wrap of hessian or crepe or something around the lead pipe to stop the tar dripping while it was poured.
Some but not all DNOs would then sweat (solder) a wire to the lead outer of the cable for to provide an earth in the vicinity of the supply. 

Mike.

I remember my father-in-law talking about how the Manchester electricity board (EB) prohibited the connection of house earths to their (the EB's) earth at the board (CU) (~ late '40s, early '50s), and how it was only later that the hard connection between the EB's  earth and the local house earth. Ahh, the good old days of lead sheathed cables.

mapj1 said:

Some but not all DNOs would then sweat a wire to the lead outer of the cable for to provide an earth in the vicinity of the supply.

Some of us still have that arrangement.

mapj1 said:

Some but not all DNOs would then sweat a wire to the lead outer of the cable for to provide an earth in the vicinity of the supply.

Some of us still have that arrangement.